Whether it's for the big screen's countless biopics or for a magazine spread, we bring you Tinseltown's most famous doppelgangers.

Hollywood biopics: Actors who take on famous faces

Meryl Streep as Margaret Thatcher

Meryl Streep is tackling the role of a lifetime - although she's had many - playing former British Prime Minister Margaret Thatcher in the upcoming film, 'The Iron Lady.' The flick follows Thatcher's historical rise to power and journey to becoming the first and only female Prime Minister in Britain's history.